An electrical connector may provide signal connections between electronic devices using signal contacts. The electrical connector may include a leadframe assembly that has a dielectric leadframe housing and a plurality of electrical contacts extending therethrough. Typically, the electrical contacts within a leadframe assembly are arranged into a linear array that extends along a direction along which the leadframe housing is elongated. The contacts may be arranged edge-to-edge along the direction along which the linear array extends. The electrical contacts in one or more leadframe assemblies may form differential signal pairs. A differential signal pair may consist of two contacts that carry a differential signal. The value, or amplitude, of the differential signal may be the difference between the individual voltages on each contact. The contacts that form the pair may be broadside-coupled (i.e., arranged such that the broadside of one contact faces the broadside of the other contact with which it forms the pair). Broadside or microstrip coupling is often desirable as a mechanism to control (e.g., minimize or eliminate) skew between the contacts that form the differential signal pair.
When designing a printed circuit board (PCB), circuit designers typically establish a desired differential impedance for the traces on the PCB that form differential signal pairs. Thus, it is usually desirable to maintain the same desired impedance between the differential signal contacts in the electrical connector, and to maintain a constant differential impedance profile along the lengths of the differential signal contacts from their mating ends to their mounting ends. It may further be desirable to minimize or eliminate insertion loss (i.e., a decrease in signal amplitude resulting from the insertion of the electrical connector into the signal's path). Insertion loss may be a function of the electrical connector's operating frequency. That is, insertion loss may be a greater at higher operating frequencies.
Therefore, a need exists for a high-speed electrical connector that minimizes insertion loss at higher operating frequencies while maintaining a desired differential impedance between differential signal contacts.